I turned OFF the DSP on my CLX + 2x BF212 subs. My room is 40 feet long so it has low room nodes and allowed the DSP to be OFF. I also turned OFF the factory CLX cross-over point. It seems to have been too low for my taste. The subs were far too THUMP, THUMP as the upper harmonics weren't good enough from the CLX to allow proper bass tonality until I upped the cross-over to 55 Hz. The difference is HUGE over what the DSP and factory settings provided. I won't ever go back to the factory setting and DSP in my situation. BASS tonality, POP, SLAM and reach are all better. I had to turn the 25 Hz setting DOWN several dB with the factory setting / DSP to try and remove the heavy artifacts of not enough upper bass harmonics. Now, 25 Hz trim is set to "0" and the bass is not only cleaner with proper upper harmonic info, but now the lowest bass can go lower and not sound like a big dead fish thrown on a wooden dock, THUMP.
For PHASE, I turned one sub OFF and stuck my head between the BF212 and CLX and turned the phase knob until the volume was at a maximum. Turn that sub OFF and repeated for the other sub. This should be pretty close although get a friend to do the KNOB while you are seated in front of the speakers is the best. Another trick is to set the SPEAKER out of PHASE (switch the polarity on both speakers) and listen for the LEAST bass with the subs PHASE knob turned. Some hear this minimum bass better than a maximum. Once you hear the minimum bass, your set, now switch the speakers back to normal polarity.
In a smaller room, I'd turn OFF the factory cross-over and try a manual cross-over point by ear. A small room may be better with the DSP "ON" to remove aggressive room nodes but I'd cycle that ON / OFF, too and see what's best.
The stereo BF212 sound SO, SO much better in my case set-up manual. I would not trust the factory cross-over / DSP to be the best. Your ear is still better. A sub has to play the proper UPPER frequencies as well as lower to blend right. My CLX weren't cutting it till I used the subs upper reach to fill in the hole as high as 55 Hz.
